<title>扩展二叉树</title><link href="http://hzoi.com/tomorrow.css" rel="stylesheet"><div class="ui existing segment"><pre><code><span class="pl-cm">/*</span>
<span class="pl-cm">ABDF..GJ..K...CEH..I...</span>
<span class="pl-cm">*/</span>
<span class="pl-c1">//A B D F . . G J . . K  .  .  .  C  E  H  .  .  I  .  .  .</span>
<span class="pl-c1">//0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22</span>
<span class="pl-cp">#include</span><span class="pl-cpf">&lt;iostream&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span><span class="pl-cpf">&lt;string&gt;</span><span class="pl-cp"></span>
<span class="pl-cp">#include</span><span class="pl-cpf">&lt;cstdio&gt;</span><span class="pl-cp"></span>
<span class="pl-k">using</span> <span class="pl-k">namespace</span> <span class="pl-n">std</span><span class="pl-p">;</span>
<span class="pl-n">string</span> <span class="pl-n">fs</span><span class="pl-p">;</span>
<span class="pl-kt">int</span> <span class="pl-nf">tail</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">root</span><span class="pl-p">){</span>
	<span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">fs</span><span class="pl-p">[</span><span class="pl-n">root</span><span class="pl-p">]</span><span class="pl-o">==</span><span class="pl-sc">&#39;.&#39;</span><span class="pl-p">)</span><span class="pl-k">return</span> <span class="pl-n">root</span><span class="pl-p">;</span>
	<span class="pl-k">else</span> <span class="pl-k">return</span> <span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">)</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">);</span>
<span class="pl-p">}</span>
<span class="pl-kt">void</span> <span class="pl-nf">m</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">root</span><span class="pl-p">){</span>
	<span class="pl-kt">int</span> <span class="pl-n">l</span><span class="pl-o">=</span><span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-p">);</span>
	<span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">l</span><span class="pl-o">-</span><span class="pl-n">root</span><span class="pl-o">==</span><span class="pl-mi">0</span><span class="pl-p">)</span><span class="pl-k">return</span><span class="pl-p">;</span>
	<span class="pl-k">else</span> <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">l</span><span class="pl-o">-</span><span class="pl-n">root</span><span class="pl-o">==</span><span class="pl-mi">2</span><span class="pl-p">)</span><span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">fs</span><span class="pl-p">[</span><span class="pl-n">root</span><span class="pl-p">];</span>
	<span class="pl-k">else</span><span class="pl-p">{</span>
		<span class="pl-n">m</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">);</span><span class="pl-c1">//left</span>
		<span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">fs</span><span class="pl-p">[</span><span class="pl-n">root</span><span class="pl-p">];</span>
		<span class="pl-n">m</span><span class="pl-p">(</span><span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">)</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">);</span><span class="pl-c1">//right</span>
	<span class="pl-p">}</span>
<span class="pl-p">}</span>
<span class="pl-kt">void</span> <span class="pl-nf">b</span><span class="pl-p">(</span><span class="pl-kt">int</span> <span class="pl-n">root</span><span class="pl-p">){</span>
	<span class="pl-kt">int</span> <span class="pl-n">l</span><span class="pl-o">=</span><span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-p">);</span>
	<span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">l</span><span class="pl-o">-</span><span class="pl-n">root</span><span class="pl-o">==</span><span class="pl-mi">0</span><span class="pl-p">)</span><span class="pl-k">return</span><span class="pl-p">;</span>
	<span class="pl-k">else</span> <span class="pl-k">if</span><span class="pl-p">(</span><span class="pl-n">l</span><span class="pl-o">-</span><span class="pl-n">root</span><span class="pl-o">==</span><span class="pl-mi">2</span><span class="pl-p">)</span><span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">fs</span><span class="pl-p">[</span><span class="pl-n">root</span><span class="pl-p">];</span>
	<span class="pl-k">else</span><span class="pl-p">{</span>
		<span class="pl-n">b</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">);</span><span class="pl-c1">//left</span>
		<span class="pl-n">b</span><span class="pl-p">(</span><span class="pl-n">tail</span><span class="pl-p">(</span><span class="pl-n">root</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">)</span><span class="pl-o">+</span><span class="pl-mi">1</span><span class="pl-p">);</span><span class="pl-c1">//right</span>
		<span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">fs</span><span class="pl-p">[</span><span class="pl-n">root</span><span class="pl-p">];</span>
	<span class="pl-p">}</span>
<span class="pl-p">}</span>
<span class="pl-kt">int</span> <span class="pl-nf">main</span><span class="pl-p">(){</span>
	<span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;expand.in&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;r&quot;</span><span class="pl-p">,</span><span class="pl-n">stdin</span><span class="pl-p">);</span>
	<span class="pl-n">freopen</span><span class="pl-p">(</span><span class="pl-s">&quot;expand.out&quot;</span><span class="pl-p">,</span><span class="pl-s">&quot;w&quot;</span><span class="pl-p">,</span><span class="pl-n">stdout</span><span class="pl-p">);</span>
	<span class="pl-n">cin</span><span class="pl-o">&gt;&gt;</span><span class="pl-n">fs</span><span class="pl-p">;</span>
	<span class="pl-n">m</span><span class="pl-p">(</span><span class="pl-mi">0</span><span class="pl-p">);</span><span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">endl</span><span class="pl-p">;</span>
	<span class="pl-n">b</span><span class="pl-p">(</span><span class="pl-mi">0</span><span class="pl-p">);</span><span class="pl-n">cout</span><span class="pl-o">&lt;&lt;</span><span class="pl-n">endl</span><span class="pl-p">;</span>
	<span class="pl-k">return</span> <span class="pl-mi">0</span><span class="pl-p">;</span>
<span class="pl-p">}</span>
<span class="pl-c1">//A B D F . . G J . . K  .  .  .  C  E  H  .  .  I  .  .  .</span>
<span class="pl-c1">//0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22</span>
</cpde></pre></div>